Mine roof support equipment

ABSTRACT

A mine roof support canopy is provided with an air-flow inducing device arranged to extract dust laden and and/or dust associated with the ventilation air flow and to direct the induced air flow away from the ventilation air flow.

United States Patent 1 1 Agnew et al. Nov. 4, 1975 MINE ROOF SUPPORTEQUIPMENT 3,387,889 6/1968 Ziemba et al 299/12 3, 8 2 299 12 X 1 1 JamesMalcolm 3,212,252 5/1212 x Collis James, both of Englanii FOREIGNPATENTS OR APPLICATIONS [73] Asslgnee: Coal Industry (Patems) Limited2,051,875 4/1972 Germany 61/45 D London, England 22 F'l d: M l 1974 1 1ear Primary Examiner-Paul R. Gilliam [21] Appl. NO-I 4 ,341 AssistantExaminer'David H. Corbin Attorney, Agent, or Firm-James C. Wray [30]Foreign Application Priority Data Mar. 16, 1973 United Kingdom 12738/73[57] ABSTRACT [52] US. Cl 61/45 D (:1. ..1 A mine roof upport anopy isprovided an air- Fleld of Search 6l/45 flow inducing device arranged toextract dust laden 299/12 and and/or dust associated with theventilation air flow and to direct the induced air flow away from the[56] References Cited ventilation air flow.

UNITED STATES PATENTS 2,032,404 3/1936 Fisher 261/116 11 Claims, 4Drawing Figures US. Patent Nov. 4, 1975 Sheet 1 of 2 FIG. 2.

FIGJ.

US, Patsm Nov. 4, 1975 Sheet 2 of2 3,916,631

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MINE RGOF SUPPORT EQUIPIVENT This invention relates to mine roof supportequipment and in particular although not exclusively the mine roofsupport equipment for installation along a longwall face.

It is conventional practice in an underground mine to have a pluralityof mine roof supports installed side-byside along the length of alongwall working face. As the working face advances each of the roofsupports, in turn is withdrawn from its mine roof supporting position,advanced towards the working face and reset to the mine roof.Unfortunately, if the mine roof is of a friable material, when theconventional roof support is withdrawn from its supporting position,broken rock material tends to fall from the sides of the roof engagingmember into the main ventilation air flow along the face. The brokenrock material usually contains a relatively high proportion of fineparticles which are carried by the ventilation air flow giving rise todust clouds.

An object of the present invention is to provide mine roof supportequipment which reduces the above mentioned dust problem.

According to the present invention mine roof support equipment comprisesat least one extensible hydraulic prop, a roof canopy supported by theprop, and apparatus for inducing air flow, the apparatus being arrangedalong the roof canopy.

Preferably, the apparatus comprises a member providing an elongatedpassage which is open at one end and a fluid outlet nozzle arranged todirect a jet of fluid along the passage towards the open end.

Advantageously, air-inlet means extend longitudinally along the memberand in which case they may comprise a slot formed in the wall of themember and extending longitudinally along the member.

Preferably, the slot is generally wedge shaped, being tapered inwardlytowards the open end of the passage.

The cross-sectional area of the passage may get smaller away from theopen end of the passage.

The cross-sectional area of the passage may get smaller towards the openend of the passage.

The opposite end of the passage to the open end may be closed by ahinged flap.

The air-inlet means may be constituted, at least in part, by having theopposite end of the passage to the said open end at least partly open.

Advantageously, the roof support equipment comprises control means whichcontrol the supply of fluid to the fluid outlet nozzle.

By way of example only, one embodiment of the present invention will bedescribed with reference to the accompanying drawings in which:

FIG. 1 is an incomplete perspective view of mine roof support equipmentconstructed in accordance with the present invention;

FIG. 2 is an incomplete end view of FIG. 1 drawn on an enlarged scale;

FIG. 3 is a longitudinal section through a detail of FIG. l; and

FIG. 41 is an end view of the detail of FIG. 3.

Referring to FIGS. 1 and 2 of the drawings, these show a part of a mineroof support installed along a longwall coal face in an underground coalmine. In the drawing only a part of one roof support is shown but in 2operation a plurality of similar supports are installed side-by-sidealong the whole length of the working face.

The roof support comprises a plurality of legs 10 which are carried on afloor mounted base (not shown) and which support a roof canopy 11extending from adjacent to the working face towards the goaf. Thedirection of the main ventilation current along the face is indicated byarrow X.

The roof support comprises apparatus 20 for inducing air flow, theapparatus being described in detail with particular reference to FIGS. 3and 4. The apparatus 20 is secured along the downstream side edge of theroof canopy 11 by means (not shown) for example brackets bolted to theroof canopy. In other embodiments of the invention the apparatus isbuilt into the roof canopy.

The apparatus 20 comprises a tubular member 21 providing an elongatedpassage 22 which is open at one end 23 and which is closed at the otherend by a hinged flap 24. The flap can be raised to allow access to thepassage 22.

A fluid outlet nozzle 25 is mounted on a radial arm 26 extending withinthe passage 22, the fluid supply being fed from a hose (not shown) viathe arm to the nozzle. The nozzle is arranged to direct a jet of fluid,for example a liquid such as water, towards the open end 23 of thepassage.

A generally wedged-shaped slot 27 is formed in the wall of the tubularmember 21 and extends longitudinally along one side of the member. Theslot 27 is tapered inwardly towards the open end 23 of the passage. Aportion of the base of the tubular member 21 is cut away so that thecross-sectional area of the passage reduces towards the closed end, thecut-away portion of the circular tube being replaced by a plate 28.

In modifications of the apparatus the cross-sectional area of thepassage approaching the open end 23 may reduce.

In further modifications of the apparatus the passage is other thancircular in cross-section for example, the passage may have a square,rectangular or oval cross section.

In still further modifications of the apparatus the fluid outlet nozzleis located adjacent to the wall of the member. Some modifications of theapparatus comprise a plurality of fluid outlet nozzles.

In operation of the apparatus 20, fluid for example water, is fed to theoutlet nozzle 25 via the radial arm 26 and is discharged as a jetdirected towards the open end 23 of the passage 22. The jet of water isarranged to impinge on the wall of the passage and induces an air flowalong the passage towards the open end of the passage, fresh air beingdrawn into the passage through the slot 27 which forms air inlet means.The slot 27 is tapered so that the resistance to air flow passingthrough any one portion of the slot reduces as the distance of theportion from the noule 25 is increased. Thus, fresh air tends to flowthrough the slot 27 along the whole length of the slot.

The cross-sectional area of the passage is reduced towards the closedend to ensure that a substantially constant air flow velocity isachieved along the length of the passage, i.e. where the quantity of airflow along the passage is less, the cross-sectional area of the passageis correspondingly reduced.

In the operation of the working face, as the face advances each of theroof supports is advanced in turn towards the working face. To advance aroof support,

the operator activates a control valve block (not shown) to retract thelegs until the roof canopy 11 is clear of the mine roof. When the roofcanopy is just clear of the roof an advancing ram (not shown) anchoredto an armoured conveyor arranged along the working face advances theroof support. When the support is fully advanced the legs 10 areextended until the roof canopy is supporting the mine roof. Theoperation is then repeated with the next adjacent support.

One problem which frequently occurs when the mine roof is of a friablematerial is that when a conventional roof canopy is lowered from themine roof, broken rock material tends to fall from the side of the roofcanopy into the main ventilation air flow. The broken rock materialusually contains a relatively large proportion of fine particles whichare carried by the ventilation air flow giving rise to dust clouds.

However, with the roof support as shown in FIGS. 1 or 2 of the drawings,when the operator activates the control valve block to advance thesupport, control means (not shown) are provided on the roof supportwhich feed a liquid, usually water, along a hose (not shown) to theoutlet nozzle 25 within the passage. The water jet so produced inducesan air flow out of the open end of the passage towards the goaf, airbeing drawn into the passage through the slot 27. Thus any fineparticles of mineral falling over the side of the roof canopy 11 aredrawn through the slot 27, into the passage 22 and then dischargedthrough the open end 23 into the goaf. During the passage of theparticles through the jet of water a high proportion tend to becomewetted by the water and thereby fall to the goaf floor. The remainderare directed away from the main ventilation air flow and rather thanforming a dust cloud tend to gradually settle onto the goaf floor.

When the roof canopy is reset to the mine roof, the control means cutoff the water supply to the nozzle 25. The hinged flap 24 enables anoperator to remove any particles of rock which may have settled insidethe passage 22.

In modifications of the invention apparatus for inducing an air flow isprovided on each side edge of the roof canopy.

We claim:

1. Mine roof support equipment comprising at least one extensiblehydraulic prop, a roof canopy supported by the prop, and air flowinducing means for extracting 4 dust from near the roof canopy, the airflow inducing means including a member mounted along the roof canopy, anair-inlet means in the member for admitting dust and means mounted inthe member to draw dust through the air-inlet means.

2. Equipment as claimed in claim 1, in which the member has an elongatedpassage which is open at one end, and wherein the means mounted in themember is a fluid outlet nozzle arranged to direct a jet of fluid alongthe passage toward the open end.

3. Equipment as claimed in claim 2, in which the air- .inlet meansextend longitudinally along the member.

4. Equipment as claimed in claim 3, in which the airinlet means comprisea generally wedge shaped slot formed in the wall of the member andextend longitudinally along the member.

5. Equipment as claimed in claim 4, in which the slot is taperedinwardly towards the open end of the passage.

6. Equipment as claimed in claim 5, in which the cross-sectional area ofthe passage reduces in a direction away from the open end of thepassage.

7. The mine roof support apparatus of claim 1 wherein the roof canopyhas a side edge, and wherein the air flow inducing means is mounted onthe side edge of the roof canopy.

8. The mine roof support equipment of claim 7, wherein the roof canopyextends longitudinally in a direction toward a working face of a mineand has side edges extending longitudinally, and wherein the air flowinducing means is mounted on the roof canopy along a longitudinallyextending side edge of the roof canopy.

9. The mine roof support equipment of claim 8, wherein the equipment ismounted adjacent a main ventilation current flowing transverse to alongitudinal direction of the roof canopy, and wherein the member ismounted along a side edge of the roof canopy downstream with respect tothe main ventilation current.

10. The mine roof support equipment of claim 7, wherein the memberextends substantially all along the side edge of the roof canopy.

, 11. The mine roof support equipment of claim 7, wherein the air flowinducing means has a longitudi nally extending inlet slot positionedoutward from the side edge of the roof canopy.

1. Mine roof support equipment comprising at least one extensible hydraulic prop, a roof canopy supported by the prop, and air flow inducing means for extracting dust from near the roof canopy, the air flow inducing means including a member mounted along the roof canopy, an air-inlet means in the member for admitting dust and means mounted in the member to draw dust through the air-inlet means.
 2. Equipment as claimed in claim 1, in which the member has an elongated passage which is open at one end, and wherein the means mounted in the member is a fluid outlet nozzle arranged to direct a jet of fluid along the passage toward the open end.
 3. Equipment as claimed in claim 2, in which the air-inlet means extend longitudinally along the member.
 4. Equipment as claimed in claim 3, in which the air-inlet means comprise a generally wedge shaped slot formed in the wall of the member and extend longitudinally along the member.
 5. Equipment as claimed in claim 4, in which the slot is tapered inwardly towards the open end of the passage.
 6. Equipment as claimed in claim 5, in which the cross-sectional area of the passage reduces in a direction away from the open end of the passage.
 7. The mine roof support apparatus of claim 1 wherein the roof canopy has a side edge, and wherein the air flow inducing means is mounted on the side edge of the roof canopy.
 8. The mine roof support equipment of claim 7, wherein the roof canopy extends longitudinally in a direction toward a working face of a mine and has side edges extending longitudinally, and wherein the air flow inducing means is mounted on the roof canopy along a longitudinally extending side edge of the roof canopy.
 9. The mine roof support equipment of claim 8, wherein the equipment is mounted adjacent a main ventilation current flowing transverse to a longitudinal direction of the roof canopy, and wherein the member is mounted along a side edge of the roof canopy downstream with respect to the main ventilation current.
 10. The mine roof support equipment of claim 7, wherein the member extends substantially all along the side edge of the roof canopy.
 11. The mine roof support equipment of claim 7, wherein the air flow inducing means has a longitudinally extending inlet slot positioned outward from the side edge of the roof canopy. 